Differential phosphorylation of the β2 integrin CD11b/CD18 in the plasma and specific granule membranes of neutrophils
Differential phosphorylation of the β2 integrin CD11b/CD18 in the plasma and specific granule membranes of neutrophils
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中性粒细胞血浆和特定颗粒膜中 β2 整合素 CD11b/CD18 的差异磷酸化
DOI:
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发表时间:
1997
影响因子:
5.5
通讯作者:
S. Abramson
中科院分区:
文献类型:
--
作者:
J. Buyon;M. Philips;J. Merrill;S. Slade;J. Leszczynska;S. Abramson
Neutrophil aggregation is mediated by the β2 integrin CD11b/CD18, which has limited expression on the surface membrane of resting cells but is recruited from intracellular organelles after cell activation. We have previously found that CD11b/CD18 newly translocated to the plasma membrane does not contribute to adhesion but must be modified to be functional. Because neutrophil aggregation induced by phorbol myristate acetate (PMA) is accompanied by de novo phosphorylation of the CD18 cytoplasmic tail, we sought to determine whether CD11b/CD18 phosphorylation is separately regulated in the different cellular compartments. Accordingly, [32P]‐labeled CD11b/CD18 was immunoprecipitated from purified neutrophil‐specific granule or plasma membrane lysates. In plasma membrane fractions, as in whole cell lysates, CD18 became phosphorylated in cells exposed to PMA but not in untreated cells or cells treated with N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP). The a chain, CD11h, was phosphorylated under all conditions. In contrast, only marginal phosphorylation of specific granule‐associated CD18 or CD11b was observed. Calyculin A, an inhibitor of serine/threonine phosphatases (ppl > pp2a), induced strong phosphorylation of CD18 in the plasma membrane but not in the specific granules. Addition of intact specific granule membranes to the plasma membranes from PMA‐treated neutrophils markedly decreased phosphorylation in both CD11b and CD18 subunits. These data suggest that the phosphorylation of CD11b/CD18, which accompanies neutrophil activation, is limited to plasma membrane‐associated molecules. Phosphorylation, either constitutive or induced, is absent in the specific granule membranes. The difference may be due to a specific granule‐associated phosphatase, probably distinct from ppl. Therefore adhesion‐competent plasma membrane CD11b/CD18 and adhesion‐incompetent specific granule CD11b/CD18 differ in their state of phosphorylation. J. Leukoc. Biol. 61: 313–321; 1997.
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DOI:
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发表时间:
1990
期刊:
Journal of immunology (Baltimore, Md. : 1950)
影响因子:
--
作者:
Buyon,JP;Slade,SG;Reibman,J;Abramson,SB;Philips,MR;Weissmann,G;Winchester,R
通讯作者:
Winchester,R
DOI:
10.1172/jci113623
发表时间:
1988
期刊:
The Journal of clinical investigation
影响因子:
--
作者:
Philips,MR;Buyon,JP;Winchester,R;Weissmann,G;Abramson,SB
通讯作者:
Abramson,SB
DOI:
--
发表时间:
1992
期刊:
Journal of immunology (Baltimore, Md. : 1950)
影响因子:
--
作者:
Neuman,E;Huleatt,JW;Vargas,H;Rupp,EE;Jack,RM
通讯作者:
Jack,RM
DOI:
--
发表时间:
1988
期刊:
Journal of immunology (Baltimore, Md. : 1950)
影响因子:
--
作者:
Buyon,JP;Abramson,SB;Philips,MR;Slade,SG;Ross,GD;Weissmann,G;Winchester,RJ
通讯作者:
Winchester,RJ
DOI:
--
发表时间:
1990
期刊:
Journal of immunology (Baltimore, Md. : 1950)
影响因子:
--
作者:
Merrill,JT;Slade,SG;Weissmann,G;Winchester,R;Buyon,JP
通讯作者:
Buyon,JP